Curious bionic features

Ok, so I've been curious for awhile now, but can't find much by goggling. I am wondering about all the stuff on the top of the DROID bionic.

So the thing on the left of Motorola logo is the front facing camera, but to the right there are 3 objects. The far right one is the notification light. But what are those other two camera looking things? Curiosity really has gotten the best of me

The accelerometer is inside I believe. I think those are a proximity sensor and a light sensor for autobrightness and to know when to turn the lights on the capacitive buttons. If you put your finger over them the capacitive buttons will light up.